Patent GB-1063200-A (GB)
Title: Blade guiding and supporting structure for band saws
Inventor: CLELAND CHARLES EMMETT
IPC: B23D55/08
Filed: 1965-10-14
Abstract: 1,063,200. Sawing. CONTINENTAL MACHINES Inc. Oct. 14, 1965, No. 43604/65. Heading B5L. A band saw machine has the back edge of the operative portion of its band saw between guide means 14 supported by a substantially flat backer band 23 coplanar with the band saw, and an entry guide 38 has spaced jaws to embrace substantial portions of the backer band and the band saw to hold the same in coplanar relationship, the guide being movable to permit the backer band to follow the saw into a workpiece. The machine has a base 8 on which a cutting head 9 is pivotally mounted, the head containing pulleys about which the band saw runs, one of the pulleys being driven by an electric motor; an hydraulic cylinder may effect pivoting of the head to feed the saw to and from the workpiece. The portion of the band saw which effects cutting is twisted to a vertical position by spaced guides 14 having shoes 15, Fig. 2 (not shown), mounted at the lower end of arms 18 adjustably secured to a beam 19 on the head 9. The shoes engage opposite sides of the saw and the back edge of the saw engages the axial faces of rollers 16; in an alternative embodiment, the shoes 15 are replaced by rollers. The backer band 23, which abuts the back edge of the band saw between the guides 14 to prevent deformation of the saw during sawing so that a relatively uniform tension is maintained throughout the width of the saw, has a thickness no greater than the toothed edge of the saw, a width two or three times that of the saw, and is secured by screws 25 to the arms 18. The arms can be urged apart by a turnbuckle 30 engaging screws secured to the arms to apply tension to the backer band. In an alternative embodiment, Fig. 13 (not shown), the tension is applied to the backer band by adjusting a nut 36 which abuts a third arm 33 secured to the beam 19 and engages a screw 34 on an arm 18 to slide the arm along the beam. The entry guide 38 is disposed between the arms 18 and consists of a block having a slit 39, Figs. 4-6 (not shown), which receives the backer band 23 and a substantial part of the saw 11 and defines rigid jaws 40. The guide may have ears 43 which slidably engage slots 44 in the arms. The backer band may be the same thickness as the toothed edge of the saw, have the same thickness as the back edge of the saw, the slit in the guide being the same thickness, Fig. 11 (not shown), or the backer band may have a wider edge 26, Fig. 12 (not shown), corresponding to the thickness of the toothed edge of the saw. During the initial part of a cutting operation, the backer band and a substantial part of the saw are within the slit 39 so that the jaws 40 maintain the coplanar relationship of the band and saw, and as sawing progresses, the entry guide abuts the workpiece as the saw cuts a kerf therein, the backer band then entering the kerf so as at all times to abut the back edge of the saw. The entry guide may be urged by springs or gravity towards the workpiece. In a further embodiment in which the cutting portion of the saw 11, Fig. 14 (not shown), runs vertically, the backing band 48 is secured to a lower post 47 below the table 45 of the machine and an upper post 46 vertically adjustable on a support 53 by a screw 54 to tension the band. The entry guide 55 may be held manually on the backer band and saw until the backer band enters the kerf cut by the saw.